1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to providing closed loop transmit diversity.
2. Background
Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). The UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time Division-Synchronous Code Division Multiple Access (TD-SCDMA). The UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSPA) and similar derivatives, which provide higher data transfer speeds and capacity to associated UMTS networks.
In addition, HSPA protocols can allow devices to communicate in a continuous packet connectivity (CPC) mode to improve overall network performance. For example, as part of operating in CPC mode, devices can implement discontinuous transmission (DTX) at least in part by refraining from transmitting control data to a base station and/or powering off a transmitter where there is no such data to transmit. Similarly, devices can implement discontinuous receive (DRX) at least in part by powering off a receiver when no data is to be received from the base station. CPC mode can conserve network resources, improve power consumption at the device, etc.